The beginning of Chapter 5 of this novel is key for a number of reasons. At the end of Chapter 4 we have just encountered a serious crisis. Because of the blood lust that Jack has unleashed with his pig hunting, the signal fire was left to go out, and a ship that could have rescued the boys passed by. Having called a meeting, Ralph therefore has to consider how he can address this vital issue with the boys and make them see the disaster that has just occurred. As he ponders how to tackle the meeting, he experiences a kind of epiphany which shows he is wise beyond his years:
Suddenly, pacing by the water, he was overcome with astonishment. He found himself understanding the wearisomeness of this life, where every path was an improvisation and a considerable part of one's waking life was spent watching one's feet. He stopped, facing the strip; and remembering that first enthusiastic exploration as though it were part of a brighter childhood, he smiled jeeringly.
Until this point, there has been an element of which the whole island experience has been like some sort of childish game - a fun field trip with various activities. However, now Ralph suddenly realises the serious situation they are in and he begins to fear what might happen to the boys if they are not able to attract a ship for help. He grows up, as is summed up in a sentence so important that it is given a whole paragraph to itself:
This meeting must not be fun, but business.
Ralph therefore experiences a moment of sudden understanding about the situation he and the boys are in and how serious it is. He recognises the responsibility that is placed upon him as leader to impress upon the boys that this is not a game, and that this is (as it will become) a struggle for survival.